# Trigonometric functions¶

Let us do some maths here!

## No proofs¶

We include no proofs whatsoever.

## Integration¶

As the derivative of \(\sin x\) is \(\cos x\), and that of \(\cos x\) is \(-\sin x\), we have

\[\int_{a}^{b}\cos x dx = \sin b - \sin a
\int_{a}^{b}\sin x dx = \cos a - \cos b\]

Isn’t that beautiful?